Referring to FIG. 8, a conventional selective one-way wrench 80 includes a handle 92, an annular head 81, an annular gear 86, a direction controller 87 and a direction switch 90. The annular head 81 is formed at an end of the handle 92. The annular head 81 defines a first space 82, a second space 83 communicated with the first space 82, a third space 89 communicated with the second space 83 and a recess 84 communicated with the third space 89. The annular gear 86 is rotationally put in the first space 82. The annular gear 86 includes a toothed external face 99 formed thereon. The direction controller 87 is put in the second space 83. The direction controller 87 includes two pawls 94 and 95 and a spring 88 installed between the pawls 94 and 95. The pawl 94 includes a toothed face 96 formed thereon. The pawl 95 includes a toothed face 97 formed thereon. The direction switch 90 is rotationally installed in the recess 84 of the handle 92 and partially put in the third space 89 for bringing the toothed face 96 of the pawl 94 or the toothed face 97 of the pawl 95 into engagement with the toothed external face 99 of the annular gear 86.
The present invention is therefore intended to obviate or at least alleviate the problems encountered in prior art.